[v9-resend,26/54] dyndbg: change __dynamic_func_call_cls* macros into expressions

Commit Message

Jim Cromie July 16, 2024, 6:57 p.m. UTC

The Xe driver's XE_IOCTL_DBG macro calls drm_dbg() from inside an if
(expression).  This breaks when CONFIG_DRM_USE_DYNAMIC_DEBUG=y because
the invoked macro has a do-while-0 wrapper.

   if (cond && (drm_dbg("expr-form"),1)) {
      ... do some more stuff
   }

Fix it by changing __dynamic_func_call_cls{,_no_desc} macros into
expressions, by replacing the do-while-0s with a ({ }) wrapper.

In C, all legal expressions are also legal statements, as converted by
the trailing semi-colon in a statement-style macro invocation:

   drm_dbg("statement form");

Signed-off-by: Jim Cromie <[e-mail]>
---
 include/linux/dynamic_debug.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 4a9b9cd53eb7..c958085e0df4 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -287,20 +287,20 @@  void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  * (|_cls):	adds in _DPRINT_CLASS_DFLT as needed
  * (|_no_desc):	former gets callsite descriptor as 1st arg (for prdbgs)
  */
-#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do {	\
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) ({	\
 	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);	\
 	if (DYNAMIC_DEBUG_BRANCH(id))				\
 		func(&id, ##__VA_ARGS__);			\
-} while (0)
+})
 #define __dynamic_func_call(id, fmt, func, ...)				\
 	__dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt,		\
 				func, ##__VA_ARGS__)
 
-#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do {	\
+#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) ({	\
 	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);		\
 	if (DYNAMIC_DEBUG_BRANCH(id))					\
 		func(__VA_ARGS__);					\
-} while (0)
+})
 #define __dynamic_func_call_no_desc(id, fmt, func, ...)			\
 	__dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT,	\
 					fmt, func, ##__VA_ARGS__)